A security official helping to protect Princess Anne was arrested in a raid by nine immigration enforcement officials, separated from his toddler and held in immigration detention after the Home Office was tipped off that his relationship with the child’s mother had broken down, the Guardian has learned.

South African Lydon Van Der Westhuizen, 29, had not committed any criminal offence when the enforcement officials banged on his door on the morning of 6 February. In fact at the end of last year he received high-level clearance enabling him to work in the security industry after undergoing thorough criminal and background checks in both the UK and his home country.

The enforcement officers arrested him and took him to Harmondsworth immigration removal centre near Heathrow. He was released six days later.

An engineer by profession, Van Der Westhuizen came to the UK from South Africa at the end of 2016 after falling in love with a British woman whom he met when she was visiting his home country.

The couple got married in London in January 2017 and their daughter was born in February 2017. Van Der Westhuizen was granted a spouse visa, valid until July 2019. However, the relationship broke down at the beginning of 2018 and he moved out of the marital home. He is devoted to his daughter and a family court order gives him access to her twice a week.

Since securing a three-year permit from the Security Industry Authority [SIA] – a Home Office agency – last December, he has been working for a top company offering “covert security”. Its advertised services include close protection, event and corporate security. Those it offers protection to include members of the royal family, celebrities, politicians and some of the wealthiest people in the UK including Russian oligarchs and Arab sheikhs. Along with royals and the super-wealthy Van Der Westhuizen has worked with Simon Cowell, Mila Kunis and David Blane.

The Home Office told the Guardian that it informed the SIA on 22 October 2018 that Van Der Westhuizen had the right to work. On the basis of this information SIA issued the three-year security permit licensing him in the frontline role of door supervisor. Yet just a week later on 30 October 2018 the Home Office said his leave was curtailed and that officials had made this decision two months earlier.

Officials said they informed Van Der Westhuizen by email on 31 August that his leave to remain would be curtailed in 60 days’ time – an email he said he never received. He told the Guardian he believed that as he is still married, although separated, his current spousal visa, which expires in July 2019, is still valid. He is applying for a parental visa from the Home Office so he can continue to parent his British daughter.

The Home Office was unable to provide an explanation to the Guardian about why it green lighted the three–year security permit on 22 October. Officials would say only that there was “a crossover period”.

Van Der Westhuizen said: “Why was I allowed to help look after Princess Anne and then a week later they did this to me?”

He said he had felt claustrophobic locked in a cell in Harmondsworth and had seen rats and mice there.

“I love the UK and I love my daughter. I’ve always worked hard here and paid my taxes. I’m relieved to have been released from detention but I’m so upset and nervous about everything now.”

His barrister, Nishan Paramjorthy, head of Paramount Chambers, said: “Lydon was whisked to an immigration detention centre even though he had explained that he had a British citizen child and a contact order from the family court that would be jeopardised by this detention. The Home Office policy of detain now and ask questions later is ruining the lives of families and must be reviewed,” he said.

Celia Clarke, director of Bail for Immigration Detainees, which has been supporting Van Der Westhuizen, expressed concern about the case.

“This case encapsulates the degree to which detention is used as a default option and not as a last resort,” she said. “The decision to detain was not accidental, it was not random, it required planning. How anyone could think that a proportionate response to someone whose permission to be in the UK the Home Office was seeking to revoke, who had a British child and no criminal conviction, was for nine officers to bang down his door and forcibly imprison him, is unfathomable. Yet again we see routine cruelty and callousness being played out through immigration enforcement.”

A check made by the Guardian on the SIA Home Office website reveals that he is still approved and registered to provide security despite having his visa curtailed.

A Home Office spokesperson said: “When Mr Van der Westhuizen was granted a spousal visa he was informed in the same letter that if his relationship broke down or his circumstances changed he would need to apply and qualify to stay in the UK on a different basis.

“When he was informed his leave to remain would be curtailed he was given two months’ notice to apply for further leave to remain if he wished to stay in the UK.

“He had the right to work in the UK up to 30 October 2018 and if he had applied and qualified for leave to remain before this date he would have maintained his right to work.

“Mr Van der Westhuizen was issued with an SIA Door Supervisor’s licence required for guarding duties relating to a licensed premises. He does not hold a Close Protection licence, which would permit him to guard one or more individuals.”